This will be used to correctly propagate page faults backinto the guest when we could have either an ordinary pagefault or a nested page fault. In the case of a nested pagefault the fault-address is different from the originaladdress that should be walked. So we need to keep trackabout the real fault-address.We could also remove the current path of the error_code tothe fault. But this change is too invasive and outside thescope of this patch set. It will be changed and testedseperatly.